1030 NORTH PARK DR 2018-01-02 MF Import

c October 23, 2007 1030 N. Park Drive, Everett, WA Geologically I-Iazardous Areas: Geotechnical Letter G-2611 Page 3 The topography of the slope indicates that historically there has been incising into the bluff. The incising could be the result f groundwater seepage creating gradual erosion, over -steepening, which results in slumps or slides. The incising could also be from . We did not observe recent slumps or slides on the subject property or the adjacent properties. We understand the existing house was constructed in 1963. Mr. I lanson, who has resided at 1054 North Park Drive for 24 years (three houses to the southwest), indicated that he is not aware of any slides or recession on the subject property since he has resided at that address. Vegetation on the bluff consists of grasses, brush, blackberry vines, small and large trees. DISCUSSION AND RECOMMENDATIONS The bluff appears to be stable at the project site. The seepage observed on the slope does not appear to be creating slope instability. 'rhe 2006 lBC (1305.3.2) recommends a building foundation setback of I U3, or 40 teet max., however we recommend a minimum 25 foot building setback for the new garage based on the site conditions and our findings. A 25 foot setback equal to the setback of the existing garage. The existing garage appears to be supported on a spread footing foundation. No cracks or settlement was observed in the garage foundation. indicating that the garage foundation has perfornied adequately. It is our professional opinion that the proposed new garage may be constructed as proposed and described herein. The new garage may be supported on a spread footing foundation. Spread footings should be supported by dense undisturbed soil or by engineered structural fill that extends a minimum of 3-feet below the footings. To achieve 3-feet of structural fill we recommend over -excavating 2-feet, compact the subgrade soil, then place 2-feet of compacted structural fill. Structural fill below footings should create a prism that extends out and below the footing at 11-1:1V (1-Iorizontal:Vertical). Structural fill supporting foundations and slab -on - grade floors should be compacted in 10-inch loose lifts to a minimum of 95 percent of the material's maximum dry density based on ASTM D1557, Modified Proctor. GEO Group North vest, Inc. 3/6